Thread plug gauge wear testing device



Oct. 10, 1944.. G. HoHwART THREAD PLUG GAUGE WEAR TESTING DEVICE Filed Dec. 29, 1943 2 Sheets-Sheet l IN VEN TOR.

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Patented Oct. 10, 1944 THREAD' PLUG GAUGE WEAR TESTING DEVICE George Hohwart, Orchard Lake, Mich., assignor to N. A. Woodworth Company, Ferndale, Mich., a corporation of Michigan Application December 29, 1943, Serial No. 51.6,023

(Cl. 'Z3-7) 8 Claims.

the manufacturer and the user to determine me expected life of the gauge and to determine @vor in accuracy that may occur during use. lilrthermore, it is important for the manufac- :aer to know the wearing qualities as this promotes improvements particularly in the selection of metals whose wearing qualities may vary. Tests to determine the wearing qualities should, as nearly as possible, approximate wear conditions prevailing in actual use of the gauges while at the same time it is important that such tests be of accelerated character as compared to the wear that occurs in actual use.

One object of the present invention is to provide a testing machine for testing the Wearing qualities of a cylindrical thread gauge member which will obtain conditions approximating those existing during actual use of the gauge members and which will effect the tests in an accelerated manner.

Another object of the invention is to provide a mechanism such as mentioned wherein the wear means acting on the threads may be adjusted so as to secure the desired wearing condition.

Another object of the invention is to provide a wear testing mechanism of the type mentioned which is automatic so that once a test is initiated, it may be continued for any length of time desired.

Other objects of the invention will become apparent from the following description, from the drawings to which it relates and from the claims hereinafter set forth.

For a better understanding of the invention reference may be had to the accompanying drawings wherein: l

Figure 1 is an elevational View in perspective illustrating a testing mechanism constructed according to `one form of the invention.

Figure 2 is an elevational view of the mechanism shown by Figure 1 as seen from the front side thereof, with certain parts removed or in section for the purpose of clarity.

Figure 3 is an elevational view of the mechanism as seen from the right side in Figure 2.

Figure 4 is a detailed view on a larger scale and partly in cross-section showing the relation between the threaded gauge member and the threaded plug Wear member used in the mechanism.

Referring to Figures 1, 2 and 3, the base of the machine is indicated at IU and is shown as having a vertical column II projecting thereabove and which supports the operating parts of the mechanism. This column, at its upper end, as best shown by Figure 3, has a frame or bracket I2 fastened thereto, and the bracket at one side has a plate portion I3 to which a reversible motor I4 is secured. At the opposite side of the column, the bracket I2 has a tubular portion I5, which, as best shown by Figure 2, has a transverse and rather wide opening I6 intermediate its ends. The lower end of the tubular portion I5 is bifurcated as indicated at II and the bifurcated portions are adapted to be drawn towards each other by a clamping bolt I8. A quill I9 projecting upwardly into the bifurcated end of the tubular part I5 is'held closely and slidab-ly by adjustment of the clamping action of the bifurcated parts.

The quill I9 rotatably receives therein and holds against relative axial movement a spindle 23 projecting upwardly at a point above the upper end of the tubular part I5 and at such upper end, the spindle has a multiple groove pulley 24 splined thereto. A belt 25, trained about this pulley, engages a groove of a second multiple groove pulley 26 which is fastened to a shaft 2'I rotatable in the upper end of the column II. A second belt 28 engaging the pulley 2E in turn engages a third multiple groove pulley 29 fastened to the shaft of the motor I4. From this it will be apparent that operation of the motor will elfect rotation of the spindle 23 while at the same time allowing the spindle and quill to move upwardly and downwardly due to the splned connection between pulley 24 and the spindle.

The spindle 23 at its lower end has a tapered drill socket 32 which receives the tapered upper end of a shaft element 33 and the latter in turn is connected by means of a universalV joint 35. to a lower shaft element 35 having a tubular extension 36 at its lower end. Such lower end 36 of the shaft 35 is adapted to receive the shank 38 of a cylindrical thread plug gauge 39 and such shank may be locked in place by means of a set screw 40. As defined in the edition entitled Gage blanks, Commercial Standard CSS-41, promulgated by able. Ylocking means.

Vvinto the wear member.

the U. S. Department of Commerce and effective as of January 1,1941, a thread plug gauge is dei-med as follows:V A thread plug gauge is a complete internal thread gauge of either single or double-ended type, comprising handle and threaded'gauging member or members, with suitgauge comprises a handle in one, and usually in both'ends of which, a'gauging member is removably received. These gauging members are usually, but not always, made up Vof a cylindrical body which isexternally threaded, such as the body 39, and an integral tapered shank, such as the shank', adapted toghe receivedin a come plementary opening in the Aend of the ,gauge handle (not shown) and heldtherein by friction.V This type of cylindrical plug gauge member isA shown in the drawing by waybf illustration and not by'limitation. Such gauge members are adapted Yto Ybe employed to test the sizes of threaded holes in workpieces and to this end, in a double-ended cylindrical thread plug gauge, the

gauging member at one end of the "handle is of a` size complementary to the smallestithreaded hole acceptable for the yworkpiecegandgtheV gauging member at the opposite end of the handle is of a size such, that if capable oi being threaded into the threaded hole, indicates that the holeris too j large Vto be acceptable.

V:Ata point above the base Ill, an ordinary drill table'or supporting plate 45 is adjustably secured tothe column II by means of a bifurcated part 45 and a clamping screw 41. This table 45 has, upon its upper side, a smaller circular plate'portion 48 and a pan or receptacle 49 which fits this plate portion so as to receivera coolant. Within the receptacle 49 a ring 5| is fastened to the plate portion 48 by suitable means such as bolts and this ring has an overhanging rirn 52 (see Fig. 3) which engages the marginal portion of the base 54 of a wear member 55. It is to be noted that the base 54 can shiftk laterally within a small The usual thread plug VThe reversing means provided, as best'shown by Figures 2 and 3, comprises a reversing switch 60 having a switch arm 6I provided with a roller 62, This roller is disposed between a pair of collars 63 and 64 threaded ontora vertical rod 65 and thecollars are locked in adjusted position Y by lock nuts I'Il and 68. rThe rod 65 is adjustably secured to a hanger I having a bifurcated end |I adjustably clamped aboutthe lower vend of the quill I9 while the upper end of the rod is slid-y able through an opening in a stationary arm 12. AV manual control switch I4 may be provided for range of movementrbut that vertical movement is substantiallyprevented, In order to prevent turning o f the wear member, a pin 51 projects therefrom and between two lingers 159 and -59 projecting upwardly Vfrom the ring 5|. This nger engagement permits lateral shifting .of the 'wear member but the engagement isv such as to `substantially prievent any turningmovement of the wear-member.

The wear member, asbest shown by Figure Ll,

j is in the form of ablockrhaving a threaded opening 56 whichis adapted to receive the threaded portion of the plug gauge 39. While the block may be formed ofany desired material, and may .be formed of the same kind of material as the thread gauge will be used inl connection with in service, it is usually preferable to formait of cast iron.v The tank 49 isY of such depth that coolant may be placed therein to a depth, above the threads. In operation, it is desired that the plugV gaugev advance into theV wear member 55 until fully threaded thereinto'and then that the rota- Ation of the gauge Ybe reversed Vso that-it will thread itself Vout of the wear member, excepting o for a final thread engagement of one or two threads and that then the gauge member be again reversed in rotation so as to againY advance, This repeated reversal f of operation is t0 be continued for aV desired lengthv of time and in order to effect the reversal, means are provided for at desired `times.

reversing the motor I4 against substantial axial resistance.

stopping and starting the motor, it being shown as mounted on a fusebox '|5. It should be understood now that upon aV predetermined movement downwardly of the spindle and quill caused by threading'of thegauge member V39 into the wear member 55, the switch 60 will be operated to reverse the motor and then upon a predetermined upward movement of the spindle caused by reversed threading action, the switch will be A reversely operated to again reverse the motor. This reversal is continuous as long as the control switch 'I4 is closed. It is manifest that the collars 63 and 64 may be adjusted so as toeiiect revers-al of the motor atV the desired time. The

movability of thewear member allows itto'float laterally within Vlimits Aand there is suflicient tolerance to permit the wear member to tilt slightly, and thisin conjunction with the joint V911,' insures axial-alignment of the wear member with the plugl gauge.

F 01' the purpose 0f providing resistance to axial movement of the'plug gauge. so as to produce a"NVV desired degree of frictionv between the threads, both when the gauge member 39 is moving downcurved to litV the opposite sides of the quill sur-Y face. Each rod is slidable in Ya sleeve bearing I8 and the bearings are located in tubular extensions l' 9 and 89 on dametrically opposite sides of the tubular partV l5. Each of the rods 'I6 and I7 is urged inwardlyv by a screw 8| adjustably threaded through an arm 83 of a bell crank 84'. pivoted as indicated at 85 to an angular portion 85 on the tubular extension 'I9 or 89 as the case may be. The other arm of the bell crank indicated at supports a weight 9| vand this weight may beadjustably positioned along the alim 90 by means of a bolt 92 adapted t0 selectively extend through a series of openings 94 in the arm.

VFrom this, it will' be appreciated that the pressure of the brass rods I6 'and I1 against the quill' Y may be varied.

In testing one of the thread plug gauges disposed in position as shown, coolantsuch as distilled water is provided in the tank 49, as indi-y cated previously, and, after adjusting the parts as desired, the control switch 'I4 is closed. The thread plug gauge then rotates rst in one direction and then in the other so as to first thread itself into the wear member and then to thread itself almost out ofV the wear member. As this occurs, the resistance elements 'I6 and 'Il resist the axial movement of thequill and consequently when the plug gauge reverses in rotation, it must climb the threads of the wear member This holdsY true in theV downwardfrmovement of the plug gauge, but in this instance the oppositesides of the threads must pull the gauge into the wear member. While this Wear action is desirable, the use of coolant is preferred in order to eliminate the effects of heat or, in other words, it is desirable to rapidly thread the plug gauge into and out of the wear members in order to accelerate the Wear action, while at the same time to avoid the effect of heat, since in normal use, heat will not normally play any part in the wearing of a plug gauge.

Although only one form of the invention has been illustrated and described in detail, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

l. A wear testing mechanism for testing a threaded gauge member, comprising a support, a Wear member having threads for engaging the threads on the gauge member, power driven means for rotating the" members relatively so as to advance one over the threads of the other solely through interengagement of the thread thereof, and means operable to automatically effect regular reversal in relative rotation so as to repeatedly thread the members one over the other first in one direction and then in the other.

2. A wear testing mechanism for testing a threaded gauge member, comprising a, support, a wear member having threads for engaging the threads on the gauge member, power driven means for rotating the members relatively so as to advance one over the threads of the other, means operable to automatically effect regular reversal in relative rotation so as to repeatedly thread the members one over the other first 1n one direction and then in the other, and adjustable means for applying resistance to relative axial movement of the members so as to increase the friction between the threads.

3. A wear testing mechanism for testing a threaded gauge member, comprising a support, a Wear member having threads for engaging the threads of the gauge member, a reversible electric motor for rotating the members relatively so as to advance one over the threads of the other solely through interengagement of the threads thereof, and means operable to automatically eifect regular reversal of said motor at predetermined relative axial positions of said members so as to repeatedly thread the members one over the other first in one direction and then in the other and to effect such reversal without disengaging the threaded members.

4. A wear testing machine for testing a threaded gauge member comprising a support, a rotary shaft on said support and mounted for reciprocation along its axis, means for driving the shaft, a threaded wear member on the support at one end of and aligned with the shaft, a threaded gauge member on said end of the shaft and adapted to be threaded into the first member, and automatic means for effecting reversal in rotation of said shaft after the gauge member advances on the wear member a certain distance and for again reversing rotation of the shaft before the gauge member can disengage from the wear member.

5. A wear testing machine for testing a threaded gauge member comprising a support, a

rotary shaft on said support and mounted for reciprocation along its axis, means for driving the shaft, a threaded wear member on the support at one end of and aligned with the shaft, a threaded gauge member on said end of the shaft and adapted `to be threaded into the first member, means for effecting reversal in rotation of said shaft after the gauge member advances on the wear member a certain distance and for again reversing rotation of the shaft before the gauge member can disengage from the Wear member, and means for applying frictional resistance to axial movement of the shaft so as respectively to create wear pressure on opposite sides of the threads during rotation of the gauge in both directions.

6. A wear testing machine for testing a threaded gauge member comprising a support, a rotary shaft on said support and mounted for reciprocation along its axis, means for driving the shaft, a threaded wear member on the support at one end of and aligned with the shaft, a threaded gauge member on said end of the shaft and adapted to be threaded on the rst member, means for effecting reversal in rotation of said shaft after the gauge member advances on the wear member a certain distance and for again reversing rotation of the shaft before the gauge member can disengage from the wear member, and means for applying frictional resistance to axial movement of the shaft so as respectively to create wear pressure on opposite sides of the threads during rotation of the gauge in both directions, said last mentioned means comprising a sliding pin on the support pressing at one end against the shaft, a lever pivoted on the support and pressing against the other end of the pin, and a weight for swinging the lever.

'7. A wear testing machine for testing a threaded gauge comprising a support, a rotary shaft on said support and mounted for reciprocation along its axis, means for driving the shaft,

a threaded wear member on the support at one end of and aligned with the shaft, a threaded gauge member on said end of the shaft and connected thereto by means including a universal connection, and means for automatically effecting reversal in rotation of the shaft after the gauge member advances in the wear member a certain distance solely through interengagement of the threads of said members and for again reversing rotation of the shaft before the gauge member is disengaged from the wear member.

8. A Wear testing machine for testing a threaded gauge comprising a support, a rotary shaft on said support and mounted for reciprocation along its axis, means for driving the shaft, a. threaded wear member on the support at one end of and aligned with the shaft, a threaded gauge member on said end of the shaft and connected thereto by means including a universal connection, means for automatically effecting reversal in rotation of the shaft alfter the gauge member advances on the wear member a certain distance and for again reversing rotation of the shaft before the gauge member can disengage from the wear member, and means mounting the wear member on the support so that it can oat within limits to align itself with the gauge member.

GEORGE HOHWART.

imam; No. 2,360,059.

CERTIFICATE OF CORRECTION.

October 1o, 19ML. o GEoRGE HoHwART.

It is hereby certified that er'r'or appear-Ys inxthe printed specification ,of the above vnumbered patent requiring corr-seti on as follows: Page -1,` second column, lines 5 and 6, for thewor'ds "threaded gauge member and' the theded plug wear member read --thread plug gauge memberand the threaded wear member'-; page 5, first column', line 22, claim l, for "thread" read --thr'eads--g and that the saidletters Patent should be read with this correcti on thereinthatthe same may conform to the record of the oase in the Patent Office.,

Signed and sealed this 20th dayA of March, A. De 719145.

Leslie Frazer (Seal) Acting Commissioner of' Patents: 

